8mm Forum: Elmo ST-600D M - repair manual + question about part

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Posted by Terryll Loffler (Member # 888) on March 10, 2010, 03:57 PM:

HI, i am in the process of trying to get 3 elmo projectors running after picking them up recently.

i am starting with the ST-600D M. i got new belts of ebay (unfortunately they are not square but regular o-rings, and the set didn't include the frame counter belt) and put them on and the projector still is having problems.

so do you round belts cause issues?

also the take reel/back arm would not turn. so i disassembled it, and i am curious. as seen in the photo, this is a theshaft that connects the internal gears/belt to the arm.

does that shaft that the red arrow is pointing to move/turn while the outer green arrow part doesn't move?

Posted by Rick Skowronek (Member # 385) on March 17, 2010, 03:22 PM:

Teryll,

Since no one perhaps more knowledgeable than myself has answered your questio, I'll give it a try.

Having several years in audio equipment and mechanical systems design and repair,this has the distinct appearance of a shaft in a stationary bearing. In otherwords, it appears the shaft is indeed supposed to freely rotate in the bearing. You'll note the brass insert in the bearing around the shaft. This is what is called a sintered brass bearing that retains oil and is typically used in these relatively low speed, low load electromechanical equipment. It is used extensively in tape recorders and such.

If it is stuck that means the grease or oil in the bearing has dried up and created a sticky mess. The only good way to free it is to put some solvent like acetone or such on the bearing till it frees up and then rcarefully remove the shaft. Using Qtips and the solvent clean the shaft and the bearing surfaces. Using a good light machine grease, coat the shaft and bearing internals. Slide the shaft back in and wipe all traces of excess grease off. Noted that your shaft looks a little garfed up. You may want to lightly sand down any ridges created on the shaft before disassembly.

Hope this helps you.
Rick

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